Wavelength division multiplexed (WDM) optical communication systems (referred to as “WDM systems”) are systems in which multiple optical signals, each having a different wavelength, are combined onto a single optical fiber using an optical multiplexer circuit (referred to as a “multiplexer”). Such systems may include a transmitter circuit, such as a transmitter (Tx) photonic integrated circuit (PIC) having a transmitter component to provide a laser associated with each wavelength, a modulator configured to modulate the output of the laser, and a multiplexer to combine each of the modulated outputs (e.g., to form a combined output or WDM signal), which may be collectively integrated onto a common semiconductor substrate.
A WDM system may also include a receiver circuit, such as a receiver (Rx) PIC, having a photodiode, and an optical demultiplexer circuit (referred to as a “demultiplexer”) configured to receive the combined output and demultiplex the combined output into individual optical signals.
A WDM system may also include a set of nodes (e.g., devices of the WDM system that may be utilized to route the multiple optical signals, add another optical signal to the multiple optical signals, drop an optical signal from the multiple optical signals, or the like). For example, the WDM system may include a set of reconfigurable optical add-drop multiplexers (ROADMs).
A wavelength of an optical signal output from the Tx PIC may be utilized to transmit information at a fixed data rate. However, multiple optical signals may be combined into a unified channel that facilitates transmission of information at a higher data rate. The multiple optical signals may be combined into one or more super-channels for routing through a network. A super-channel may refer to a set of channels that